github actions to plan/apply multiple terraform projects

terraform.yml

name: "Terraform"

on:
  push:
    branches:
      - master
  pull_request:

jobs:
  terraform:
    name: "Terraform"
    runs-on: ubuntu-latest

    env:
      ARM_SUBSCRIPTION_ID: ${{ secrets.ARM_SUBSCRIPTION_ID }}
      ARM_TENANT_ID: ${{ secrets.ARM_TENANT_ID }}
      ARM_CLIENT_ID: ${{ secrets.ARM_CLIENT_ID }}
      ARM_CLIENT_SECRET: ${{ secrets.ARM_CLIENT_SECRET }}

    strategy:
      matrix:
        folder: ['01-demo', '02-demo']

    steps:
      - name: Checkout
        uses: actions/checkout@v2

      - name: Setup Terraform
        uses: hashicorp/setup-terraform@v1

      - name: Terraform Init
        id: init
        run: terraform -chdir=${{ matrix.folder }} init

      - name: Terraform Plan
        id: plan
        if: github.event_name == 'pull_request'
        run: terraform -chdir=${{ matrix.folder }} plan -no-color
        continue-on-error: true
      
      - name: Add PR comment
        uses: peter-evans/create-or-update-comment@v1
        if: github.event_name == 'pull_request'
        with:
          issue-number: ${{ github.event.pull_request.number }}
          body: |
            #### Directory: \`${{ matrix.folder }}\`
            #### Terraform Format and Style 🖌\`${{ steps.fmt.outcome }}\`
            #### Terraform Initialization ⚙️\`${{ steps.init.outcome }}\`
            #### Terraform Validation 🤖${{ steps.validate.outputs.stdout }}
            #### Terraform Plan 📖\`${{ steps.plan.outcome }}\`
            
            <details><summary>Show Plan</summary>
            
            \`\`\`${{ steps.plan.outputs.stdout }}\`\`\`
            
            </details>
            
            *Pusher: @${{ github.actor }}, Action: \`${{ github.event_name }}\`, Working Directory: \`${{ env.tf_actions_working_dir }}\`, Workflow: \`${{ github.workflow }}\`*`
      
      - name: Terraform Plan Status
        if: steps.plan.outcome == 'failure'
        run: exit 1

      - name: Terraform Apply
        id: apply
        if: github.ref == 'refs/heads/master' && github.event_name == 'push'
        run: terraform -chdir=${{ matrix.folder }} apply -auto-approve

      - name: Add Merge comment
        uses: peter-evans/commit-comment@v1
        if: github.ref == 'refs/heads/master' && github.event_name == 'push'
        with:
          body: |
            #### Directory: \`${{ matrix.folder }}\`
            #### Terraform Apply 📖\`${{ steps.apply.outputs.outcome }}\`
            
            <details><summary>Show Apply</summary>
            
            \`\`\`${{ steps.apply.outputs.stdout }}\`\`\`
            
            </details>
            
            *Merger: @${{ github.actor }}, Action: \`${{ github.event_name }}\`, Working Directory: \`${{ env.tf_actions_working_dir }}\`, Workflow: \`${{ github.workflow }}\`*`